1. Field of the Invention
This invention relates to a method of sampling a fluid flowing through a line by inserting a sampling device in the line and drop-wise removing a composite sample representative of the quality and quantity of the flow from the line for immediate and/or subsequent analysis.
2. Prior Art Statement
Mastitis is the most costly dairy cattle disease. Without an effective mastitis identification and control program, loss in milk production, discarded or unsalable milk, death or premature culling and decreased genetic advancement can wipe out a dairy farm. Conductivity meters have been used to note a change in an animal""s quality as it is believed that the conductivity of the milk from an animal increases with increased mastitis. Somatic Cell Count (SCC) for a herd is effective but costly and lengthy to complete as samples from each animal must be sent to a remote laboratory for testing. An on-site test is the California Mastitis Test which uses a flat paddle with a depression for collecting a sample from each quarter of the mammary. A reagent is applied to each sample to subjectively determine the amount of thickening which is representative of the amount of leukocyte cells present. Some problems with the CMT paddle test for quarters are: loss of the sample from being kicked by the animal, contamination from the environment, slowing of the milking cycle due to the manual nature of the test and finally, the CMT quarter paddle test is not representative of the entire letdown of the animal as somatic cells tend to stratify along with the butterfat over the course of the letdown. Furthermore, testing a large herd consumes a great deal of time.
It has been noted above that electronic samplers are available but generally these meters function too slowly for high-speed milking barns. Furthermore, no sample is retained from most electronic devices to determine the correlation between the multiplicity of meter tests and actual SCC.
It is known to test for the mastitis by provide for conductivity measurements in each quadrant of a milking claw by measuring the conductivity of the milk in a region in the bottom of the claw adjacent the letdown of the individual teat. For instance, see the U.S. Pat. Nos. 3,664,306, 3,695,230, 3,762,371, issued on May 23, 1972, Oct. 3, 1972 and Oct. 2, 1973, respectively, to Quayle, et al., or the U.S. Pat. No. 4,325,028 issued on Apr. 13, 1982 to Toshio Takahashi, or the U.S. Pat. No. 4,403,568 issued on Sep. 13, 1983 to Fukuhara., et al, or the U.S. Pat. No. 5,829,381 issued on Nov. 3, 1998 to Nijkamp, et al. It is also known to test for mastitis by measuring the conductivity of the milk retained in a spherical chamber disposed in the milk line which receives and retains a portion of the milk flow in a region of the chamber. For instance, see the U.S. Pat. Nos. 3,884,187 and 3,968,774 to Massie issued on Jul. 13, 1976 and Sep. 21, 1973, respectively. Conductivity of the retained portion is measured by electrical probes inserted in the retained portion of the chamber with flow continuing through the retained portion through a drain port disposed in the bottom of the retainer. It is believed that testing at the bottom of the claw only tests the heavier fractions of the milk which is not representative of the entire letdown. It has been found that the above mentioned devices are too slow for high-speed milking operations and require costly sophisticated electronic gear to measure the samples. Furthermore, no sample is retained for correlation with the actual SCC.
Yet further known is a method to extract a sample for determining milk fat content from a milk accumulator in the milking line. The sampling time is dependent upon milk flow as measured by historical data of the animal being milked. A solenoid valve opens and closes based on signals provided by controlling means receiving a flow signal from a separate flow metering device placed before the sampler in the milking line. For instance, see the U.S. Pat. Nos. 5,645,012 and 5,746,153 issued on Jul. 8, 1997 and May 5, 1998, respectively, to Tilman Hoefelnayer. A costly and complicated device with separate electronic controlling means is required to sample by this method. Furthermore, samples are taken at the bottom of the accumulator or the discharge chamber thus sampling only the heavier fractions of milk thus giving a false indication of the total letdown. No test is made for Somatic Cell Count though a sample is retained. The BouMatic volume meter used in the tests below also samples from the bottom of the accumulator.
It is further known to provide a filter in an inline chamber to test the opacity of milk particles accumulated on the filter by optical means as a measure of the amount of mastitis in an individual animal. The milk from each animal is segregated at individual milking stations so an infected animal may be segregated from the herd and treated and the milk retained from admixing with milk from uninfected animals. The entire letdown is measured as the filter accumulates throughout the milking cycle though no sample is removed from the letdown. For instance, see the U.S. Pat. No. 4,385,590 issued on May 31, 1983 to Bruce Mortensen. No sample from the letdown is retained for correlation to actual Somatic Cell Count and the inline filter chamber coupled with the optical means of measuring is costly and complicated.
Additionally, it is known to provide an inline coupler connected by tubing to a pumping unit that continuously draws milk through the tube returning all but timed samples to the milk line. The timed samples are taken approximately every 5 minutes by a cam actuated timer through a two way valve. The inline coupler has a depression in its inner bore at the inlet of the sampling tube to provide a reservoir of milk to be sampled. For instance, see U.S. Pat. Nos. 5,388,549 and 5,572,946 issued on Feb. 14, 1995 and Nov. 12, 1996, respectively, to Michael Holroyd. It is believed that the reservoir in this device tends to accumulate only the heavier fractions of the milk, thus the samples may not be representative of the flow. It is also believed that samples taken at 5 minute intervals would not be representative of the entire letdown. Holroyd does not retain a sample for correlation.
It is also known to take a drip sample by forcing a portion of fuel into an open container during bunkering a ship. For instance, see www.martechnic.de/dripsam.htm.
Another known milk weighing device accumulates the entire letdown in an accumulator drawing off only air in the accumulator. The accumulator is then agitated by blowing air through a central tube having its end adjacent the bottom of the accumulator. The accumulator is then emptied by drawing the contents of the accumulator through the central tube wherein a sample is taken in a venturi disposed in the vacuum line leading to a storage tank. For instance, see the U.S. Pat. No. 4,016,832 issued on Apr. 12, 1977 to Philippus Kiestra. The sample collector stops sampling when full and would therefore be representative of only part of the letdown. The agitation described in this patent is similar to pouring back and forth between buckets as is proscribed in sample preparation for DHIA testing. It is also believed that since the sampling container is not in the milking line and is not cleaned between the milking of separate animals, cross-contamination of samples is highly possible giving false indications to the herdsman. No disposition of the sample is indicated.
Finally, it is known to provide an inline xe2x80x9cTxe2x80x9d for positively receiving a sampling tube connector therein. When the sampling tube connector is locked into the xe2x80x9cTxe2x80x9d, one end of a hollow needle punctures a plug in the xe2x80x9cTxe2x80x9d. The other end of the needle has a resealable sheath which may be repeatedly punctured with that end of the needle when sampling tubes are put into the sampling tube connector. Blood pressure of the patient fills the sampling tubes through a single port in the end of the needle. For instance, see the U.S. Pat. No. 5,620,008 issued on Apr. 15, 1997 to Shinar, et al. Though a sample is taken during the blood draw, the tubes fill very quickly and thus are not representative of the entire donation.
Most sampling devices in the prior art are costly to purchase, operate and maintain. Many require an associated micro or minicomputer to operate. Many of these devices also require the sampling chamber and associated electric measuring probes to be made as a part of the claw or installed in a costly container in the flow line in a milking operation thereby further driving up the cost of installation, operation and maintenance. Therefore, it is an object of this invention to provide an inline sampling device adapted to remove a representative sample drop-wise from a fluid line wherein a sampling probe having at least two fluid receiving, volume relief ports is movably disposed in the fluid line.
It is a further object of this invention to provide an inline sampling device having a sampling probe with at least one fluid receiving, volume relief port movably disposed therein wherein at least one fluid receiving, volume relief port is directed toward the incoming flow.
An additional object of this invention is to provide a sampling device and method of sampling which has a higher correlation of California Mastitis Test (CMT) results with actual Somatic Cell Count (SCC) from the entire letdown of a milked animal than the CMT average of all four quarters to actual SCC level of the individual animal.
Still another object of this invention is to provide an inline sampling device adapted to remove a representative sample drop-wise from a fluid flowing through a fluid line, the inline sampling device comprising a body, a sampling probe and a sampling container wherein the body has an inlet, an outlet with the sampling probe having at least two fluid receiving, volume relief ports movably disposed in the body between the inlet and the outlet.
Another feature of this invention is to provide an inline sampling device comprising a body, a sampling probe and a sampling container wherein the sampling probe has at least one fluid receiving, volume relief port directed toward the incoming flow of the fluid flowing through the fluid line.
Significant to this invention is providing an inline sampling device comprising a body, a sampling probe and a sampling container wherein the sampling probe has a first fluid receiving, volume relief port disposed remote from a lower inside surface of the fluid line and at least a second fluid receiving, volume relief port disposed remote from the first fluid receiving, volume relief port and wherein the second fluid receiving, volume relief port may be disposed above a central axis of the fluid line.
Another important feature of this invention is to provide an inline sampling device comprising a sampling probe having at least one fluid receiving, volume relief port adapted to remove a portion of the volume of the sampling container equal in volume to each drop of fluid received in the sampling container through the at least one fluid receiving, volume relief port.
A valued feature of this invention is to provide an inline sampling device comprising a sampling probe having at least two fluid receiving, volume relief port wherein one of the fluid receiving, volume relief port is adapted to sample heavier molecular weight fractions of the fluid flowing through the fluid line and wherein at least one other fluid receiving, volume relief port is adapted to sample lighter molecular weight fractions of the fluid flowing through line.
Another important object of this invention is to provide an inline sampling device comprising a sampling probe having at least one fluid receiving, volume relief port wherein the sampling probe has one said fluid receiving, volume relief port disposed adjacent a lower inside surface of the fluid line and at least one other fluid receiving, volume relief port disposed remote from the one fluid receiving, volume relief port.
Yet still important to this invention is to provide an inline sampling device having a sampling container removably affixed to the sampling device wherein the sampling container is a standard milk sampling vial snap-fitted in a retaining groove disposed in the body of the sampling device and wherein the retaining groove is concentric with the sampling probe, matches upper lip of sampling vial thereby sealed the sampling vial to the body in the retaining groove. The cap for the sampling vial may be received over a boss on an exterior surface of the body.
Yet another object of this invention is to provide an inline sampling device comprising a body, a sampling probe and a sampling container, the sampling device adapted to remove a representative sample drop-wise from a fluid flowing through a fluid line wherein the body has an inlet, an outlet with the sampling probe fixedly disposed therein between the inlet and the outlet and wherein the sampling probe has at least one fluid receiving, volume relief port adapted for receiving a multiplicity of drop-wise samples of fluid flowing through the fluid line and for discharging a portion of the volume of sampling container into the fluid line in exchange for each drop-wise sample received in the sampling container.
It is an important to dairymen that a feature of this invention is to provide a method of sampling a fluid, such as milk, flowing through a fluid collection line wherein the fluid comprises a stratified fluid wherein at least one layer of higher molecular weight fractions is disposed below at least one layer of lower molecular weight fractions, the method comprises the steps of installing a sampling device in the fluid line, receiving representative samples of the fluid through a sampling probe disposed in a body of the sampling device and accumulating the representative samples throughout the duration of the flow through the line, such as throughout the entire letdown of a milking animal, in a standard sampling vial associated with the sampling device and wherein the method further comprises the step of sampling from at least one layer of higher molecular weight fractions and from at least one layer of lower molecular weight fractions.
It is also important that the method of sampling of this invention provides a sampling probe extending into a fluid flowing through a fluid line, the probe having at least two fluid receiving, volume relief ports disposed in a sidewall thereof that are spaced along the length of the sampling probe wherein the method comprises the step of sampling a stratified flow in the fluid line from at least one layer of higher molecular weight fractions with one fluid receiving, volume relief port and sampling from at least one layer of lower molecular weight fractions with another fluid receiving, volume relief port.
It is particularly advantageous to dairymen that a method of sampling from a fluid, such as milk, flowing through a fluid line provide for moving a sampling probe within a body of sampling device disposed in the milking line between the claw and pipeline connection wherein the method comprises the step of moving at least one fluid receiving, volume relief port disposed in the sampling probe into a different layer of higher molecular weight fractions of the fluid flow and moving another fluid receiving, volume relief port into a different layer of lower molecular weight fractions of to accommodate for different levels of fluid flow.